Trial of an Online Group Psychotherapy Intervention for Common Mental Health Disorders

The goal of this clinical trial is to understand how to deliver online group therapy for adults with common mental health problems in a personalised way. This study will test a new online group therapy program for various common mental health problems like anxiety and depression. The therapy is based on an approach called the Unified Protocol, which includes eight modules teaching different coping skills. The therapy will be delivered via a video call and a website, which will also have helpful videos and information about coping skills. Aims: 1. Does changing the order of the therapy modules affect how well treatment works or how many patients drop-out of treatment? 2. Do some modules work better for different patients based on their individual features and if patients receive the therapy module that is most likely to be helpful for them first, does it mean they have a better chance of feeling better by the end of treatment? 3. Does online group therapy work as well to treat common mental health problems as standard care (individual cognitive behavioural therapy \[CBT\])? Hypotheses: 1. Changing the order of therapy modules will not change how well therapy works or how many people drop-out. 2. Patients with specific profiles (based on their individual characteristics) will benefit more from some treatment modules and will see greater improvements in their symptoms if they received their best therapy module before other modules 3. There will be no differences in overall treatment outcome or dropout rates when comparing online group therapy vs. individual CBT Researchers will compare whether delivering the modules in different orders, with five different versions of the treatment, to see if changing the order of therapy modules affects how well it works or drop-out rates. Researchers will test how best to match patients to the most helpful parts of treatment for them. The group therapy outcomes and costs will also be compared to data from patients who have had individual CBT to see how the intervention compares to standard care. Participants will: * Complete online symptom questionnaires before treatment starts and before each therapy session * Attend 12 weekly group therapy sessions delivered by a video call on a website (called Uplift-X). * Access online resources like videos and practice exercises to use between therapy sessions. * Complete the online symptom questionnaires again at the end of treatment and 6 months later.